I would not contradict anything said in this thread, but I would add that switches do sometime fail, therefore do include a pullable circuit breaker for the servo power where the pilot can reach it in flight. Mine is a little ways across the cockpit, but I do have it. The failure is an unlikely event, but the consequences relatively severe.
I used primarily fuses in my airplane, but that is one of 4 circuit breakers I have. The others are one for each of two alternator over-voltage circuits, and a buss cross-tie which is for convieniece only.